A pure-Python memory-efficient packed representation for bit arrays
Project description
This class presents a pure-Python memory-efficient packed representation for bit arrays.
Version 2.2 includes a couple of bug fixes and a new method runs() that returns a list of strings that are consecutive runs of 1’s and 0’s in the bit vector. This version also allows for chained invocations of circular bit shift operations.
Version 2.1 includes enhanced support for folks who use this class for computer security and cryptography work. You can now call on the methods of the BitVector class to do Galois Field GF(2^n) arithmetic on bit arrays. This should save the users of this class the bother of having to write their own routines for finding multiplicative inverses in GF(2^n) finite fields.
Version 2.0 provides much additional functionality that was requested by folks in the data mining community.
The class supports the following operators/methods:
__getitem__
__setitem__
__len__
__iter__
__contains__
__getslice__
__str__
__int__
__add__
__eq__, __ne__, __lt__, __le__, __gt__, __ge__
__or__
__and__
__xor__
__invert__
__lshift__
__rshift__
__add__
count_bits
count_bit_sparse (faster for sparse bit vectors)
deep_copy
divide_into_two
gcd
gf_divide (for divisions in GF(2^n))
gf_MI (for multiplicative inverse in GF(2^n))
gf_multiply (for multiplications in GF(2))
gf_multiply_modular (for multiplications in GF(2^n))
hamming_distance
intValue (for returning the integer value)
isPowerOf2
isPowerOf2_sparse (faster for sparse bit vectors)
jaccard_distance
jaccard_similarity
length
multiplicative_inverse
next_set_bit
pad_from_left
pad_from_right
permute
rank_of_bit_set_at_index
read_bits_from_file
read_bits_from_fileobject
reset
reverse
runs
shift_left for non-circular left shift
shift_right for non-circular right shift
slice assignment
setValue
unpermute
write_to_file
write_bits_to_fileobject
